/*
Copyright (C) 2015 Marien Raat

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#pragma once

// This class takes one dimensional double array as a heightmap and a
// double as the water level.
// It returns a one dimensional array of booleans where true signifies
// land and false signifies sea.
// Lakes are not generated by this class

// Note: The heightmap and the water levelshould be normalized between
// 0.0 and 1.0 for this class.
class LandMapGenerator {
public:
    LandMapGenerator();

    // Sets the water level
    void setWaterLevel(double waterLevel);

    // Returns a pointer to this->landMap
    bool *generateLandMap(
                          // The heightmap array to derive the land
                          // map from.
                          // Normalized between 0.0 and 1.0.
                          double *heightmap,
                          // The width of the heightmap
                          unsigned width,
                          // The height of the heightmap
                          unsigned height,
                          // If the current landMap should be overwritten
                          // or a new one should be created
                          bool overwriteOldMap);
    // A pointer to an one dimensional boolean array of the
    // same size as the heightmap. true signifies land, while false
    // signifies sea.
    // Will contain valid data if generateLandMap has been called
    bool *landMap;
private:
    double waterLevel;
    bool firstMap;

    // Writes to the points adjacent to (x, y) if they are part of the
    // sea, when (x, y) is part of the sea.
    // Returns true to signify that it found at least one new part of
    // sea. Returns false if it failed to find a new point of sea.
    bool spreadFrom(
                    // x and y coordinates to spread from
                    unsigned x,
                    unsigned y,
                    // The width and height of the belowSeaLevelMap
                    // and the landMap
                    unsigned width,
                    unsigned height,
                    // The map that signifies whether a point is below
                    // sea level
                    bool *belowSeaLevel,
                    // The map to write to which points are below sea
                    // level.
                    bool *landMap);
};
